Retrograde entry antegrade placement for femoral artery access

ABSTRACT

A Retrograde Entry Antegrade Placement (REAP) method and apparatus facilitate the antegrade (i.e., in the direction of blood flow) placement of endovascular devices for treatment of lower extremity arterial disease. Initially, a retrograde entry is made into the arterial system of a patient at an entry point with a curved needle, which then exits at an exit point proximal to the entry point, with a first wire then passed through the lumen of the curved needle. From the skin exit point, a Dual-Lumen Access Director (DAD) device is advanced in the antegrade direction down the first wire in a first lumen and enters the CFA  1  lumen. A second wire is passed down a second lumen in the DAD device and follows the SFA lumen in the antegrade direction. The DAD device is removed, and a standard dilator sheath is inserted over the second wire and the endovascular treatment begins.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/415,188 filed on Nov. 18, 2010 titled “Retrograde AccessAntegrade Placement For Femoral Artery Access” and U.S. ProvisionalApplication Ser. No. 61/444,928 filed on Feb. 21, 2011 titled“Retrograde Entry Antegrade Placement For Femoral Artery Access” both ofwhich are incorporated herein by reference in their entirety for allthat is taught and disclosed therein.

BACKGROUND

1. Rationale for Choice of the Femoral Artery in Vascular Access

The common femoral artery is the primary entry site for interventionalvascular access. The majority of procedures involving interventions uponmajor arteries, including those of the limbs, neck, viscera, heart andhead, are performed through needle entry into the common femoral artery.In the vast majority of cases, certainly greater than 95% in the USA,needle entry into the common femoral artery is done via a retrogradestick (i.e., a needle enters the artery in a direction opposite the flowof blood).

Antegrade stick (i.e., a needle enters the artery in the same directionas the flow of blood), in which the operator stands on the patient'sleft facing the feet, is rarely employed. There are several reasons forthe facts stated above.

The first reason is operator-based. The stance and posture of aretrograde approach to the common femoral artery are quite natural. Mostpersons (85-92%) are right-hand dominant. An operator standing at thesupine patient's right groin and facing towards the patient's head willfind an ideal ergonomic position for right hand maneuvers involvingreach, grasp, pinch, push-pull, pronation and supination of the hand andwrist. The operator's natural range of motion of the combined finger,wrist, and elbow joints very comfortably blankets a work area centeredupon the groin.

The second reason is target size. The common femoral artery (CFA) lumendiameter has been extensively studied in health and disease states, andin a patient population typically provides a minimum lumen diameter of 4mm to 6 mm. In many patients the lumen diameter reaches 8 to 10 mm.Catheter bores for common vascular interventions typically range from 6French (diameter 2 mm) to 8 French (diameter 2.7 mm). The CFA thuseasily accommodates the outside diameters of tubular instrumentation.

Length of the target vessel is also important, as the approach angle ofthe needle determines potential tip placement at each depth. In 200angiographic measurements the mean common femoral artery length was 43.3mm, and it was given as 22.5 to 50 mm in 75% of a large number of directmeasurements.

The above explains why the CFA is frequently chosen as a target. It mustbe explained, however, why the retrograde rather than the antegradestick route is the predominant choice. FIGS. 1A, 1B, and 1C show thetarget segment of the common femoral artery (CFA). An internal view ofBody 3 is shown in FIG. 1A depicting CFA 1 (shown in solid lines),Inguinal Ligament 4, Profunda Femoris Artery (PFA) 7 (shown in dottedlines), Superficial Femoral Artery (SFA) 8 (shown in dashed lines),Anterior Superior Iliac Spine (ASIS) 9, Right Femur 10, Femoral Head 11,and Coccyx 12. One reason the retrograde rather than the antegrade stickroute is the predominant choice is the longer Target Segment 2 length ofCFA 1 when Needle 6 approaches retrograde (FIG. 1B) rather than TargetSegment 2′ of CFA 1 when Needle 6 approaches antegrade (FIG. 1C). Thisis due to the multiple topographic curvatures of Body 3 as well asobstruction by the Inguinal Ligament 4 and the Abdominal Protuberance 5.Additionally, both the topographic window for needle entry into theskin, and the Swath 13, 13′ (the conical three-dimensional zone throughwhich Needle 6 may pass in order that its tip will strike Target Segment2, 2′) are also smaller in the antegrade stick approach (FIG. 1C) to CFA1 as compared with the traditional retrograde pathway (FIG. 1B).

Body habitus is frequently abnormal in patients undergoing treatment forvascular disease. In the retrograde stick approach to CFA 1, operatorshave long been comforted in their use of a traditional retrograde needleplacement by the fact that the approach angle and swath of the needlepathway are not materially altered by patient bulk (see FIG. 2A withnormal Body 3 and Abdominal Protuberance 5 and FIG. 2B with abnormalBody 3′ and Abdominal Protuberance 5′). Longer needles may be needed totraverse the thicker body wall, but the approach angle and Swath 13 foraccess need not change.

In the antegrade stick technique, however, body habitus substantiallynarrows Swath 13′ of potential needle passage (see FIGS. 3A and 3B).Because CFA 1 Target Segment 2′ is also reduced in length, the technicalchallenges in the antegrade approach to a large patient are ofteninsurmountable.

The ideal approach angle for a needle entering CFA 1 is between 30 and45 degrees. If much steeper, 60 to 90 degrees, the subsequent placementof larger bore devices will lead to crimping or, worse, laceration(“cheese-wire” effect) of the arterial wall, with hemorrhage. In almostno cases of antegrade approach to CFA 1 is the ideal angle not blockedby Inguinal Ligament 4 and other structures superior to the groin (seeFIG. 1).

A third technical hindrance to catheterization of SFA 8 via an antegradedirected needle stick is the problem of the Wire-Extrusion Vector 14(see FIG. 4A). Operators have long experienced the ease with which theretrograde stick approach places a wire almost unfailingly in the iliacsystem. This is because of the unique spacial positioning of the needletip aimed retrograde. Because of the natural approach angle whichmatches with the direction of CFA 1 as it passes under Inguinal Ligament4 and becomes the posterior-directed External Iliac Artery (EIA) 38 (seeFIG. 9), extrusion of the wire from Needle Bore 15 is virtually alwaysaimed in the right direction.

In the case of an antegrade directed needle stick, the opposite is true.The mandatory vertical and posterior aim of Needle Bore 15 andWire-Extrusion Vector 14′ almost always ensures that the wire will beextruded in the direction of PFA 7, instead of entering the SFA 8.Because Swath 13′ for Needle 6 approach is so narrow in the antegradetechnique, the needle tip itself can move through only a very smallswing angle as the operator attempts to correct its aim, misdirectingthe wire into the PFA 7 (see FIGS. 4B and 4C).

The fourth reason is control and closure of the arteriotomy. Intentionalentry into SFA 8 for placement of larger (5 French or greater) devices,is problematic. At the origin of SFA 8 from CFA 1 the diameter of theartery drops precipitously to a lumen diameter of less than 5 mm, asflow divides from CFA 1 into two substantial branch channels, SFA 8 andPFA 7. SFA 8 is not only smaller in diameter but possesses decreasedarterial wall strength and integrity in comparison to CFA 1. Surgeonswill often find the SFA 8 wall friable and unforgiving when it issutured, a problem compounded by the artery's smaller lumen. SFA 8 istherefore avoided whenever possible as a site in which to originate abypass graft, with CFA 1's stronger and larger structure beingpreferred. FIG. 5A shows an 8 French (diameter 2.7 mm) Sheath 16entering into a CFA 1 having a Lumen 17 of 6 mm in diameter and a WallThickness 18 of 2 mm. Also shown for comparison is 8 French Sheath 16entering into a SFA 8 having a Lumen 19 of 4 mm in diameter and a WallThickness 20 of 1.5 mm.

The catheter interventionalist placing a sheath in an artery faces anadditional problem. The tubular mass inserted creates a roughly circulararteriotomy corresponding to the outside diameter of that sheath. Thisarteriotomy must then be closed in some way, i.e., sealed, once thesheath is removed. 8 French Sheath 16 inserted into CFA 1 produces anarteriotomy which occupies much less of a percentage circumference ofthe vessel than in SFA 8 (see FIG. 5B). Compared to CFA 1, an 8 Frencharteriotomy in SFA 8 produces a much larger break in the circularintegrity of SFA 8, allowing Lumen 19 to gape when 8 French Sheath 16 isremoved. Given two tubes, one larger and one smaller, a slit of the samelength made transversely in each will disrupt shape-retention propertiesand tubular integrity much more in the smaller than in the larger tube.For this reason, SFA 8 more frequently demonstrates bleeding ordisruption when entered with large bore devices.

Studies have shown as much as a 10% rate of pseudoaneurysm formationwhen sizeable catheters are deliberately placed into SFA 8. This islikely due in part to the difficulty in compressing SFA 8 manually aftersheath removal. CFA 1 can be compressed by fingertip pressure on theskin overlying the puncture site, because the round bony surface of theFemoral Head 11 lies immediately beneath (see FIG. 1). SFA 8 has nocorresponding bone structure deep to it which would allow effectivemanual compression. In the final analysis, the safest and most certainpathway for a large-bore catheter into the vascular tree is via anarteriotomy in the CFA 1.

2. Anatomy of the Femoral Artery

Anatomy of the femoral zone is complex and can be deceiving to theunschooled. CFA 1 lies in a depression, Femoral Triangle 21, seenimmediately below the fold of the groin (see FIG. 6). Emerging frombeneath Inguinal Ligament 4 as it leaves the pelvic cavity, CFA 1 (notvisible in FIG. 6) enters the thigh at a point equidistant from ASIS 9and the pubic symphysis (not shown in FIG. 6). CFA 1 is a continuationof a large artery—the EIA 38 (see FIG. 9). The vessel simply changesnames to become CFA 1 as it crosses beneath Inguinal Ligament 4.

In the upper thigh, CFA 1 resides between the Femoral Vein 22 mediallyand the femoral nerve laterally (not shown in FIG. 6), in a triangularspace with distinct boundaries. Superiorly is Inguinal Ligament 4;laterally, Sartorius Muscle 23; and medially, Adductor Longus Muscle 24.Deep to the femoral artery, separating it from the spherical FemoralHead 11, is the psoas major tendon (not shown in FIG. 6). Superficial tothe femoral artery, forming a roof over Femoral Triangle 21 in the upperthigh is the Fascia Lata 25.

3. Topography of Femoral Artery Access

Body-surface planes and curvatures in the femoral depression tend toprohibit an antegrade approach. The femoral arteries (CFA 1, PFA 7, andSFA 8) reside in the femoral triangle concavity. Access to the femoralbranches is affected by the depth of that depression, as well as theother compound curvatures of the abdomen, pelvis, pubis and thighs (seeFIG. 7). In smaller and thinner persons, the curvatures are stillpresent but may be less pronounced. But in heavier bulkier individualsthe mounding and angulation of tissue can present formidable obstacles.

There are four prominent topographic curvatures shown in FIG. 7.Abdominal Protuberance 5 is the abdominopelvic protuberance, sometimesexaggerated as a pannus, containing the muscular abdominal wall, andfatty tissue, which if large, may also include the anterior peritoneumcontaining the small intestine and even the colon. Transverse Groove 26is the furrow or crease formed where the inguinal canal meets the upperthigh. Muscular Curvature 27 is the mound of medial and lateralmusculature bounding the depression of the Femoral Triangle 21.Sub-Pubic Pit 28 is the empty space defined by the confluence of thepubis and inner thighs.

4. Known Difficulties of the Antegrade Approach

Antegrade access is not widely touted in the literature, nor utilizedextensively, due to its technical difficulty. For the foregoing reasons,medical authors have repeatedly cautioned against the antegradeapproach. Dr. Giuseppe Biondi-Zoccai recommends a minimum caseload of 60antegrade procedures to assure competency. Dr. Schneider noted that eventhe easier, retrograde approach resulted in less than optimal needleplacement in 56% of cases, including 13% entirely beyond the borders ofCFA 1. Dr. Schneider advocates against a routine antegrade approach. Dr.Narins emphasizes the steeper learning curve and increased risk ofvascular complications with antegrade stick of the common femoralartery.

As a result of these and other problems, operators have not embracedantegrade femoral access. Interventionalists have instead relied uponthe safety and practicality of the retrograde up-and-over technique: toreach the right leg, stick the left common femoral artery; for the leftleg, stick the right common femoral artery. Nonetheless, there areenormous advantages to be gained from the antegrade approach.

5. Impetus to Develop a Safe and Easy Antegrade Approach to the FemoralArtery

Antegrade placement and manipulation of endovascular treatment devicesis the most promising frontier for treatment of lower extremity arterialdisease. Manufactured devices for precise work in the lowerextremities—particularly if utilized to treat targets below theknee—tend to be difficult to maneuver when working over the distancesand past the multiple twisting turns involved in the retrogradeup-and-over access technique.

In the up-and-over method a catheter which enters the right commonfemoral artery retrograde must immediately track deep posteriorlyfollowing the external iliac artery down into the pelvis along thesacrum. Then it must rise abruptly within the common iliac artery,turning sharply towards the midline. The catheter then crosses theaortic bifurcation at an angle greater than 270 degrees. Another set ofacute angles ensues as the catheter backtracks through the pelvisrepeating the iliac course and curvatures in reverse. It will thenemerge beneath the inguinal ligament, cross the “speed-bump” of thecontralateral common femoral artery and its branches. At this point thecatheter must be maneuvered along a steadily narrowing pathway in thesuperficial femoral artery until it reaches another s-curve, this timein the anterior-posterior plane, as it enters the popliteal artery andtraverses the knee. Thereafter lie three successive sharp-angledtake-offs of arterial branches whose diameter is now less than 3 mm,less if badly diseased.

To accomplish this, catheters must be longer. However, the increasedlength sacrifices pushability and control. Tight atherosclerotic plaquesmust be crossed by pushing in the opposite direction of catheter path atthe target. This is not only mechanically disadvantageous, but requires“opposite-think” and 3-dimensional conceptual efforts which are notalways easy for an operator. As a result, widespread application ofcertain devices has been limited by difficulty in controlling thecatheters at distant lesions. Because of the predominant pattern ofretrograde femoral access, manufacturers have been forced to compromisedevice control for length, and performance has suffered. Effectivetherapeutic devices which function optimally in the antegrade directionhave thus been hindered in reaching a patient population which couldbenefit by their use.

There are natural advantages to the right-hand dominant operator whichaccrue when standing at the patient's right groin facing the head. Inantegrade access to the legs these advantages are also in full play.Once antegrade access is established, the operator stands at the supinepatient's left hip. So positioned, maneuvers of the operator's hands aredirected towards the target vessels, along the axis of the cathetersystem. This affords all the mechanical and spacial advantages withwhich operators are familiar with in traditional retrograde access tothe upper body.

A solution to these difficulties in access to the leg arteries would bethe development of a process which makes antegrade access easy, safe,and routine. The technique should have a short learning curve, andshould utilize device configurations with which the operator is alreadyfamiliar. Ideally it should be performed in the operator position andvia the anatomic approach most familiar to practitioners. The REAPprocedure and associated devices described below are designed to providesuch a solution.

SUMMARY OF THE INVENTION

This Summary is provided to introduce in a simplified form a selectionof concepts that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

A Retrograde Entry Antegrade Placement (REAP) method and apparatusfacilitate the antegrade (i.e., in the direction of blood flow)placement of endovascular devices (i.e., working within the lumen ofvascular structures) for treatment of lower extremity arterial disease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, and 1C show the target segment of the common femoralartery.

FIG. 2A shows the retrograde-stick approach in a normal body habitus.

FIG. 2B shows the retrograde-stick approach in a large body habitus.

FIG. 3A shows the antegrade-stick approach in a normal body habitus.

FIG. 3B shows the antegrade-stick approach in a large body habitus.

FIG. 4A shows the wire extrusion vector in the retrograde-stickapproach.

FIG. 4B shows the wire extrusion vector in the antegrade-stick approach.

FIG. 4C shows the wire extrusion vector in the antegrade-stick approach.

FIG. 5A shows a perspective view of arteriotomy comparisons between theCFA and the SFA.

FIG. 5B shows an elevation view of arteriotomy comparisons between theCFA and the SFA.

FIG. 6 shows the femoral triangle.

FIG. 7 shows body surface planes and curvatures.

FIG. 8A shows the operator, patient, and equipment in alternatepositions.

FIG. 8B shows an ultrasound-guided micropuncture entry into the SFA.

FIG. 9 shows advancing a wire into the iliac system.

FIG. 10 shows advancing the dilator and sheath, and then removing thedilator.

FIG. 11 shows the thin wire being removed.

FIG. 12 shows a thick wire being inserted.

FIG. 13 shows a curved needle being advanced over the thick wire.

FIG. 14 shows the thick wire being removed completely.

FIG. 15 shows the curved needle being advanced retrograde within theCFA.

FIG. 16 shows the curved needle exiting the CFA and the skin.

FIG. 17 shows a short stiff A wire passed through the curved needle“air-to-air.”

FIG. 18A shows the change in position of the operator and monitors.

FIG. 18B shows the curved needle starting to be removed over the A wire.

FIG. 19 shows the curved needle being removed over the A wire.

FIG. 20 shows the dual-lumen access director (DAD) advanced in theantegrade direction over the A wire and into the CFA lumen.

FIG. 21 shows bleed-back through the “D” wire lumen as the oval orificeof the DAD enters the CFA lumen.

FIG. 22 shows the DAD further advanced, with bleed-back ceasing as theoval orifice is blocked.

FIG. 23 shows the DAD being withdrawn a short distance in the retrogradedirection, and the D wire inserted in the Luer tip.

FIG. 24 shows the injection seal and side-port attached to the Luer tip.

FIG. 25 shows the D wire being passed antegrade down the SFA.

FIG. 26 shows the DAD beginning to be withdrawn.

FIG. 27 shows the DAD continuing to be withdrawn.

FIG. 28 shows the A wire withdrawn and a standard angiographic sheathand dilator passed over the D wire.

FIG. 29 shows the intended percutaneous procedure being performed in theantegrade direction.

FIG. 30 shows the needle control hub.

FIG. 31 shows a portion of the curved needle.

DETAILED DESCRIPTION Retrograde Entry Antegrade Placement (REAP) for SFAAccess

The following will describe various apparatus and various method stepsutilized in retrograde entry for antegrade placement of endovasculardevices via SFA access.

Step 1. FIG. 8A shows the operator, patient, and equipment in alternatepositions. Referring now to FIG. 8A, Operator 29 is positioned onPatient 30's right side, as for any traditional femoral artery entryangiographic procedure. The C-Arm X-Ray Machine 31 may be positionedopposite or adjacent to Operator 29 and is movable in the directionsindicated by the arrows. C-Arm X-Ray Machine 31 is used to performfluoroscopic and angiographic imaging. Monitors 32 are positioned at thepatient's left, at torso level. Referring now to FIG. 8B, ultrasound isused to acquire data including the distance from Skin 35 to CFA 1, thelumen diameter of CFA 1, and location of the orifice of the take-off ofPFA 7 and the location of the origin of CFA 1. Operator 29 utilizingpalpation and Ultrasound Transducer 33 with ultrasound transmission Gel34 sticks Needle 6 through the Skin 35 at an entry point and makes anultrasound-guided micropuncture entry into SFA 8 at a point 1-2 cmdistal from the origin of SFA 8, with Needle 6 directed in thetraditional retrograde position (see FIG. 1B). Blood 36 bleeds back fromNeedle 6 indicating to Operator 29 that the tip of Needle 6 haspunctured SFA 8. Arrow 39 indicates the direction of blood flowantegrade.

Step 2. FIG. 9 shows advancing a wire into the iliac system. Referringnow to FIG. 9, Thin Wire 37 (typically 0.014 inch diameter) is advancedthrough Needle 6 into EIA 38 of the iliac system and confirmed byfluoroscopy with C-Arm X-Ray Machine 31. Needle 6 is then removed.

Step 3. FIG. 10 shows advancing the dilator and sheath and then removingthe dilator. Referring now to FIG. 10, Micro-Puncture Dilator 40(typically 3 French) inside Sheath 41 is passed over Thin Wire 37 andinto SFA 8 in the direction indicated by Arrow 42. The Micro-PunctureDilator 40 is then removed in the direction indicated by Arrows 43leaving Sheath 41 in place.

Step 4. Referring now to FIG. 11, Thin Wire 37 is removed in thedirection indicated by Arrow 44. Referring now to FIG. 12, Thick Wire 45(typically 0.035 inch diameter) is inserted into Sheath 41 in thedirection indicated by Arrows 46 and into EIA 38 and confirmed byfluoroscopy with C-Arm X-Ray Machine 31. Sheath 41 is then removed fromSFA 8 over Thick Wire 45 in a direction opposite to Arrows 46.

In an alternative embodiment, the micro-puncture kit described above isnot used. Instead, a larger needle, such as an 18 gauge needle, is usedto puncture the skin and enter SFA 8 and then Thick Wire 45 is insertedthrough the lumen of the larger needle and into SFA 8. Steps 1-4 can bereplaced with the following steps.

Step 1′ Referring now to FIG. 8B, ultrasound is used to acquire dataincluding the distance from Skin 35 to CFA 1, the lumen diameter of CFA1, and identification of the orifice of the take-off of PFA 7 and of theorigin of CFA 1. Operator 29 utilizing palpation and UltrasoundTransducer 33 with ultrasound transmission Gel 34 sticks Needle 6through the Skin 35 at an entry point and makes an ultrasound-guidedentry into SFA 8 at a point 1-2 cm distal from the origin of SFA 8, withNeedle 6 directed in the traditional retrograde position. Blood 36bleeds back from Needle 6 indicating to Operator 29 that the tip ofNeedle 6 has punctured SFA 8. Arrow 39 indicates the direction of bloodflow antegrade.

Step 2′. FIG. 9 shows advancing a wire into the iliac system. Referringnow to FIG. 9, Thick Wire 45 (typically 0.035 inch diameter) is advancedthrough Needle 6 into EIA 38 of the iliac system and confirmed byfluoroscopy with C-Arm X-Ray Machine 31. Needle 6 is then removed.

Step 5. FIG. 13 shows a curved needle being advanced over the thickwire. Referring now to FIG. 13, Curved Needle 47 is advanced in thedirection indicated by Arrow 48 over Thick Wire 45 to the point wherethe aim of the tip is substantially horizontal or parallel to SFA 8 andCFA 1. Curved Needle 47 may be of various lengths and with differentradii in order to accommodate specific patient anatomy. Needle lengthand radii are determined from the ultrasound analysis done in step 1(see FIG. 8B).

In another embodiment, Steps 1-6 can be replaced with the followingsteps.

Step 1″ Operator 29 utilizing palpation and Ultrasound Transducer 33with ultrasound transmission Gel 34 sticks Curved Needle 47 through theSkin 35 at an entry point and makes an ultrasound-guided entry into SFA8 at a point 1-2 cm distal from the origin of SFA 8, with Curved Needle47 directed in the traditional retrograde position (see FIG. 14). Blood36 bleeds back from Curved Needle 47 indicating to Operator 29 that thetip of Curved Needle 47 has punctured SFA 8. Arrow 39 indicates thedirection of blood flow antegrade. The method continues with Step 7below.

FIG. 30 shows the needle control hub. Referring now to FIG. 30, NeedleControl Hub 72 is designed to facilitate hand motions required forarterial exit and post exit maneuvers. In endovascular diagnostic andtherapeutic work, the usual arterial access needle hub is designed forthe purpose of pushing the straight needle in the straight directiontowards an endpoint target which has depth, width and breadth, intowhich the needle tip must enter and then dwell momentarily while a wireis passed through the needle into the lumen of the artery. In the REAPmethod, Curved Needle 47 must track along the same course into the SFA 8lumen already occupied by the previously placed Thick Wire 45, and thenmust exit CFA 1 and track up a curvilinear pathway which has continuallyvarying directionality and is aimed at a topographic landmark guided byOperator 29's palpation. For this reason, Needle Control Hub 72, i.e.,the control point of the Operator 29's hand upon Curved Needle 47, mustbe somewhat bulkier and shaped to allow precise upward movement andside-to-side deflection of the needle tip. Wire Entry Orifice 73 alignswith the lumen of Curved Needle 47. Needle Control Hub 72 is linked to astiffened and tapering segment of needle diameter.

FIG. 31 shows a portion of the curved needle. Referring now to FIG. 31,certain metallurgical and strengthening and other modifications ofCurved Needle 47 are shown. Because of the upward and curvilinearvectors of force applied to Curved Needle 47, it must be modified in itsmanufacture for the purpose of strengthening its resistance to deformityduring upward tip deflecting maneuvers for arterial exit and subsequenttracking towards the skin surface. Thickening of an inner portion of theperi-lumenal Radius 74 of the needle in a tapered fashion beginning atthe hub is one such method of strengthening, along with metallurgicalcompositional alterations to provide more anti-deformational strengthalong the long-axis of the curvature. The Lumen 75 is located in theouter portion of Curved Needle 47 for additional strength. The needletip is also modified to alter its sharpening in order to focus sharpnessat a position at the tip alone of its bevel, not circumferential aroundthe bevel. This is designed to allow effective puncture of the arterialendothelial surface and arterial wall as well as tissue planes leadingto and including the skin.

Step 6. FIG. 14 shows the thick wire being completely removed. Referringnow to FIG. 14, Thick Wire 45 is withdrawn in the direction indicated byArrow 49 completely out of Curved Needle 47, and Blood 36 bleeds backfrom the Lumen 75 of Needle Control Hub 72 of Curved Needle 47.

Step 7. FIG. 15 shows the curved needle being advanced retrograde withinthe CFA. Referring now to FIG. 15, following its own curvature in asimple circular track in the direction indicated by Arrow 50, CurvedNeedle 47 is advanced retrograde within the lumen of CFA 1.

Step 8. Still referring to FIG. 15, advancement continues and bleed-backceases when Operator 29 feels Curved Needle 47 traverse the arterialwall of CFA 1.

Step 9. FIG. 16 shows the curved needle exiting the CFA and the skin.Referring now to FIG. 16, Curved Needle 47 continues to track along itssemicircular pathway towards Skin 35 at a site targeted by Operator 29,tenting up the dermis, and the bevel of the tip of Curved Needle 47 ispushed through Skin 35 at an exit point. An armored transparent gel pad(not shown in FIG. 16) can be used to receive the bevel if tenting isnot prominent, protecting Operator 29's fingers.

Step 10. FIG. 17 shows a short stiff “A” wire passed through the curvedneedle “air-to-air.” Referring now to FIG. 17, Stiff “A” Wire 51(typically 0.035 inch diameter) is passed through Curved Needle 47 inthe direction indicated by Arrows 50. This is termed an “air-to-air”wire, in that both ends are non-lumenal, although the mid-portion of thewire traverses the CFA 1/SFA 8 lumenal region. The air-to-air wire is aposition-holding device used for precise placement of the Dual-LumenAccess Director (DAD) 56 (see FIG. 20).

Step 11. FIG. 18A shows the change in position of the operator andmonitors. Referring now to FIG. 18A, Operator 29 moves in the directionindicated by Arrow 52 to the left side of Patient 30. Monitors 32 areswung in the direction indicated by Arrow 53 to the right of Patient 30at waist level, opposite Operator 29. C-Arm X-Ray Machine 31 (not shownin FIG. 18A) continues to be based on the same side as it was at thebeginning of the procedure, right or left (see FIG. 8A). Referring nowto FIG. 18B, Curved Needle 47 starts to be removed over Stiff “A” Wire51 in the direction indicated by Arrow 54.

Step 12. FIG. 19 shows the curved needle being removed over the A wire.Referring now to FIG. 19, Curved Needle 47 is removed completely fromCFA 1/SFA 8 lumenal region and Skin 35 over Stiff “A” Wire 51 in thedirection indicated by Arrows 55.

Step 13. FIG. 20 shows the Dual-Lumen Access Director (DAD) advanced inthe antegrade direction over the A wire and into the CFA lumen.Referring now to FIG. 20, in the antegrade direction Operator 29advances DAD 56 over Stiff “A” Wire 51 in the direction indicated byArrows 57. DAD 56 has “A” Wire Lumen 58 that travels from Female LuerHead 61 to the tip. DAD 56 is advanced over Stiff “A” Wire 51 through“A” Wire Lumen 58. “D” Wire Lumen 59 travels from Female Luer Head 61 toa point proximal to the tip that ends in Oval Orifice 60. DAD 56 has nonatural curvature of its own but is flexible and will conform to thecurvature of the wire over which it is placed.

Step 14. FIG. 21 shows bleed-back through the D wire lumen as the ovalorifice of the DAD enters the CFA lumen. Referring now to FIG. 21,bleed-back of Blood 36 through “D” Wire Lumen 59 and exiting from FemaleLuer Head 61 of DAD 56 is observed by Operator 29 when Oval Orifice 60of DAD 56 enters the lumen of CFA 1 in the direction indicated by Arrow62.

Step 15. FIG. 22 shows the DAD further advanced, with bleed-back ceasingas the oval orifice is blocked. Referring now to FIG. 22, as DAD 56 isfurther advanced antegrade over Stiff “A” Wire 51 bleed-back ceases asOval Orifice 60 is blocked by the wall of SFA 8 or by passing slightlybeyond the wall of SFA 8 at the site of SFA 8 entry-arteriotomy.

Step 16. FIG. 23 shows the DAD being withdrawn a short distance in theretrograde direction, and the D wire inserted in the Luer tip. Referringnow to FIG. 23, Operator 29 withdraws DAD 56 approximately onecentimeter in the retrograde direction indicated by Arrow 63. ThroughFemale Luer Head 61 and “D” Wire Lumen 59, Hydrophilic Wire 64(typically 0.035 inch diameter) is inserted in the direction indicatedby Arrow 65 for a few centimeters with J-Tip 67 of Hydrophilic Wire 64exiting Oval Orifice 60, stopping most of the bleed-back. Operator 29then proceeds either to optional step 17 or to step 18.

Step 17. [Optional] FIG. 24 shows the injection seal and side-portattached to the Luer tip. Referring now to FIG. 24, Injection Seal AndSide-Port 66 is back-loaded over Hydrophilic Wire 64 and attached toFemale Luer Head 61. Injection Seal And Side-Port 66 is flushed andde-aired by Operator 29. Contrast is injected through the side-port ofInjection Seal And Side-Port 66 using either “puff” angiography or aroad-mapping technique, both of which are well known by those skilled inthe art, placement of the J-Tip 67 of Hydrophilic Wire 64 within the SFA8 is confirmed.

Step 18. FIG. 25 shows the D wire being passed antegrade down the SFA.Referring now to FIG. 25, Under either fluoroscopic control or, peroptional step 17, angiographic imaging, J-Tip 67 of Hydrophilic Wire 64is passed in the direction indicated by Arrow 39 antegrade down thelumen of SFA 8. J-Tip 67 is shown in four different advancementpositions down the lumen of SFA 8 in FIG. 25.

Step 19. FIG. 26 shows the DAD beginning to be withdrawn. Referring nowto FIG. 26, DAD 56 is withdrawn over both Hydrophilic Wire 64 and Stiff“A” Wire 51 in the direction indicated by Arrows 68. FIG. 27 shows theDAD continuing to be withdrawn. Referring now to FIG. 27, DAD 56 iscompletely outside of the CFA 1/SFA 8 lumenal region, leaving onlyHydrophilic Wire 64 and Stiff “A” Wire 51 within the CFA 1/SFA 8 lumenalregion.

Step 20. FIG. 28 shows the A wire withdrawn and a standard angiographicsheath and dilator passed over the D wire. Referring now to FIG. 28,Stiff “A” Wire 51 is withdrawn by pulling either end, and brief pressureis held over the SFA 8 entry-arteriotomy by Fingers 69 of Operator 29 oran assistant. Operator 29 then passes in the direction indicated byArrow 70 a standard Angiographic Sheath 71 of chosen size and Dilator 76over Hydrophilic Wire 64 into the CFA 1/SFA 8 lumenal region and then inthe antegrade direction indicated by Arrow 39. Operator 29 then graspsDilator Hub 77 and removes Dilator 76 from Angiographic Sheath 71 (shownremoved in FIG. 29).

Step 21. FIG. 29 shows the intended percutaneous procedure beingperformed in the antegrade direction. Referring now to FIG. 29, theintended percutaneous endovascular procedure is now performed byOperator 29 via Angiographic Sheath 71 with Operator 29 working from theleft side of Patient 30 in the antegrade direction (see FIG. 18A).

Although the description above has been focused on the CFA 1/SFA 8vascular area, one skilled in the art will recognize that otherapplications of the method and devices described above can be applicableto other portions of the body where ease of entry in the vascular systemin one direction, and then reversal in the other direction, would beadvantageous. Thus, the methodology described above is not limited tothe CFA 1/SFA 8 vascular region. In addition, although the descriptionabove has been focused on human patients, one skilled in the art willrecognize that applications of the method and devices described abovecan be applicable to mammals or any other organism having a vascularsystem. Thus, the methodology described above is not limited to humansonly.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims. It will be understood by thoseskilled in the art that many changes in construction and widelydiffering embodiments and applications will suggest themselves withoutdeparting from the scope of the disclosed subject matter.

What is claimed is:
 1. A method for retrograde entry antegrade placementfor femoral artery access, the method comprising: (a) advancing a curvedneedle through a skin of a patient at an entry point and into a lumen ofa superficial femoral artery retrograde at a predetermined distancedistal from an origin of a superficial femoral artery until a tip of thecurved needle exits the common femoral artery and exits through the skinof the patient at an exit point proximal to the entry point; (b)advancing a first wire into and out of a lumen of the curved needle; (c)removing the curved needle completely from the first wire while leavingthe first wire in place; (d) from the exit point, advancing over thefirst wire a dual-lumen access director into the common femoral arteryantegrade and into the superficial femoral artery of the patient,wherein the dual-lumen access director receives the first wire in afirst lumen that extends from the tip of the dual-lumen access directorto the head of the dual-lumen access director; (e) advancing thedual-lumen access director until an oval orifice located proximal to thetip of the dual-lumen access director is just about to exit thesuperficial femoral artery, wherein a second lumen extends from the headof the dual-lumen access director to the oval orifice of the dual-lumenaccess director; (f) advancing a second wire down the second lumen ofthe dual-lumen access director until the tip of the second wire exitsthrough the oval orifice and into the superficial femoral artery; (g)removing the dual-lumen access director completely from the first andsecond wires while leaving the first and second wires in place; (h)removing the first wire completely from the superficial femoral arteryand the common femoral artery and out of the skin of the patient; and(i) advancing a sheath over the second wire, enabling further procedureswithin the superficial femoral artery antegrade.
 2. The method accordingto claim 1 further comprising the step of: using ultrasound analysis toacquire data including a distance from the skin to the common femoralartery, a lumen diameter of the common femoral artery, a location of anorifice of the take-off of a profunda femoris artery, and a location ofan origin of the common femoral artery.
 3. The method according to claim1 further comprising performing the following steps after step (f):back-loading over the second wire an injection seal and side port;attaching the injection seal and side port to a female Luer head of thedual-lumen access director, flushing and de-airing the injection sealand side port; injecting contrast through a side port of the injectionseal and side port; and using at least one of a “puff” angiography and aroad-mapping technique, confirming placement of the second wire withinthe superficial femoral artery.
 4. The method according to claim 1wherein step (i) further comprises the steps of: advancing a dilatorwithin the sheath over the second wire; advancing the dilator within thelumen of the common femoral artery and into the lumen of the superficialfemoral artery; and removing the dilator from the sheath.
 5. A methodfor retrograde entry antegrade placement for femoral artery access, themethod comprising: (a1) advancing a needle through a skin of a patientat an entry point and into a lumen of a superficial femoral artery; (a2)placing an initial wire through a lumen of the needle into the lumen ofthe superficial femoral artery retrograde; (a3) removing the needlecompletely while leaving the initial wire in place; (a4) advancing overthe initial wire a curved needle through the skin of the patient at theentry point and into the lumen of the superficial femoral arteryretrograde at a predetermined distance distal from an origin of thesuperficial femoral artery until a tip of the curved needle issubstantially horizontal or parallel to the superficial femoral artery;(a5) removing the initial wire completely from the curved needle; (a6)advancing the curved needle until the tip of the curved needle exits thecommon femoral artery and exits through the skin of the patient at anexit point proximal to the entry point; (b) advancing a first wire intoand out of a lumen of the curved needle; (c) removing the curved needlecompletely from the first wire while leaving the first wire in place;(d) from the exit point, advancing over the first wire a dual-lumenaccess director into the common femoral artery antegrade and into thesuperficial femoral artery of the patient, wherein the dual-lumen accessdirector receives the first wire in a first lumen that extends from thetip of the dual-lumen access director to the head of the dual-lumenaccess director; (e) advancing the dual-lumen access director until anoval orifice located proximal to the tip of the dual-lumen accessdirector is just about to exit the superficial femoral artery, wherein asecond lumen extends from the head of the dual-lumen access director tothe oval orifice of the dual-lumen access director; (f) advancing asecond wire down the second lumen of the dual-lumen access directoruntil the tip of the second wire exits through the oval orifice and intothe superficial femoral artery; (g) removing the dual-lumen accessdirector completely from the first and second wires while leaving thefirst and second wires in place; (h) removing the first wire completelyfrom the superficial femoral artery and the common femoral artery andout of the skin of the patient; and (i) advancing a sheath over thesecond wire, enabling further procedures within the superficial femoralartery antegrade.
 6. The method according to claim 5 further comprisingthe step of: confirming the placement of the initial wire into the lumenof the superficial femoral artery through fluoroscopic imaging.
 7. Amethod for retrograde entry antegrade placement for femoral arteryaccess, the method comprising: (a1) advancing a needle through a skin ofa patient at an entry point and into a lumen of a superficial femoralartery; (a2) placing a fine wire through a lumen of the needle into thelumen of the superficial femoral artery retrograde; (a3) removing theneedle completely from the fine wire while leaving the fine wire inplace; (a4) advancing over the fine wire a dilator and a sheath into thelumen of the superficial femoral artery retrograde; (a5) removing thedilator completely from the fine wire while leaving the sheath in place;(a6) removing the fine wire completely from the sheath while leaving thesheath in place; (a7) advancing a first wire through the sheath into thesuperficial femoral artery retrograde; (a8) removing the sheathcompletely from the first wire while leaving the first wire in place;(b) advancing a curved needle over the first wire through the skin ofthe patient at the entry point and into the lumen of the superficialfemoral artery until the tip of the curved needle is substantiallyhorizontal or parallel to the superficial femoral artery; (c) removingthe first wire completely from the curved needle; (d) advancing thecurved needle until the tip of the curved needle exits a common femoralartery and exits through the skin of the patient at an exit pointproximal to the entry point; (e) advancing a second wire into and out ofa lumen of the curved needle; (f) removing the curved needle completelyfrom the second wire while leaving the second wire in place; (g) fromthe exit point, advancing over the second wire a dual-lumen accessdirector into the common femoral artery antegrade and into thesuperficial femoral artery of the patient, wherein the dual-lumen accessdirector receives the second wire in a first lumen that extends from thetip of the dual-lumen access director to the head of the dual-lumenaccess director; (h) advancing the dual-lumen access director until anoval orifice located proximal to the tip of the dual-lumen accessdirector is just about to exit the superficial femoral artery, wherein asecond lumen extends from the head of the dual-lumen access director tothe oval orifice of the dual-lumen access director; (i) advancing athird wire down the second lumen of the dual-lumen access director untilthe tip of the third wire exits through the oval orifice and into thesuperficial femoral artery; (j) removing the dual-lumen access directorcompletely from the second and third wires while leaving the second andthird wires in place; (k) removing the second wire completely from thesuperficial femoral artery and the common femoral artery and out of theskin of the patient; and (l) advancing a sheath over the third wire,enabling further procedures within the superficial femoral arteryantegrade.
 8. The method according to claim 7 further comprising thestep of: confirming the placement of the fine wire into the lumen of thesuperficial femoral artery through fluoroscopic imaging.
 9. A method forvascular access, the method comprising the steps of: (a) advancing acurved needle through a skin of a subject at an entry point and into alumen of a vascular channel in a first direction until a tip of thecurved needle exits the vascular channel and exits through the skin ofthe subject at an exit point proximal to the entry point; (b) advancinga first wire into and out of a lumen of the curved needle; (c) removingthe curved needle completely from the first wire while leaving the firstwire in place; (d) from the exit point, advancing over the first wire adual-lumen access director into the vascular channel in a seconddirection opposite the first direction, wherein the dual-lumen accessdirector receives the first wire in a first lumen that extends from thetip of the dual-lumen access director to the head of the dual-lumenaccess director; (e) advancing the dual-lumen access director until anoval orifice located proximal to the tip of the dual-lumen accessdirector is just about to exit the vascular channel-wall, wherein asecond lumen extends from the head of the dual-lumen access director tothe oval orifice of the dual-lumen access director; (f) advancing asecond wire down the second lumen of the dual-lumen access directoruntil the tip of the second wire exits through the oval orifice and intothe vascular channel; (g) removing the dual-lumen access directorcompletely from the first and second wires while leaving the first andsecond wires in place; (h) removing the first wire completely from thevascular channel and out of the skin of the subject; and (i) advancing asheath over the second wire, enabling further procedures within thevascular channel in the second direction.
 10. The method according toclaim 9 further comprising the step of: using ultrasound analysis toacquire data including a distance from the skin to the vascular channel,a lumen diameter of the vascular channel, and a location of any otherstructures of interest.
 11. The method according to claim 9 furthercomprising performing the following steps after step (f): back-loadingover the second wire an injection seal and side port; attaching theinjection seal and side port to a female Luer head of the dual-lumenaccess director, flushing and de-airing the injection seal and sideport; injecting contrast through a side port of the injection seal andside port; and using at least one of a “puff” angiography and aroad-mapping technique, confirming placement of the second wire withinthe vascular channel.
 12. The method according to claim 9 wherein step(i) further comprises the steps of: advancing a dilator within thesheath over the second wire; advancing the dilator within the lumen ofthe vascular channel; and removing the dilator from the sheath.
 13. Amethod for vascular access, the method comprising the steps of: (a1)advancing a needle through a skin of a subject at an entry point andinto a lumen of a vascular channel; (a2) placing an initial wire througha lumen of the needle into the lumen of the vascular channel in thefirst direction; (a3) removing the needle completely while leaving theinitial wire in place; (a4) advancing over the initial wire a curvedneedle through the skin of the subject at the entry point and into thelumen of the vascular channel in the first direction until the tip ofthe curved needle is substantially horizontal or parallel to thevascular channel; (a5) removing the initial wire completely from thecurved needle; (a6) advancing the curved needle until the tip of thecurved needle exits the vascular channel and exits through the skin ofthe subject at an exit point proximal to the entry point; (b) advancinga first wire into and out of a lumen of the curved needle; (c) removingthe curved needle completely from the first wire while leaving the firstwire in place; (d) from the exit point, advancing over the first wire adual-lumen access director into the vascular channel in a seconddirection opposite the first direction, wherein the dual-lumen accessdirector receives the first wire in a first lumen that extends from thetip of the dual-lumen access director to the head of the dual-lumenaccess director; (e) advancing the dual-lumen access director until anoval orifice located proximal to the tip of the dual-lumen accessdirector is just about to exit the vascular channel, wherein a secondlumen extends from the head of the dual-lumen access director to theoval orifice of the dual-lumen access director; (f) advancing a secondwire down the second lumen of the dual-lumen access director until thetip of the second wire exits through the oval orifice and into thevascular channel; (g) removing the dual-lumen access director completelyfrom the first and second wires while leaving the first and second wiresin place; (h) removing the first wire completely from the vascularchannel and out of the skin of the subject; and (i) advancing a sheathover the second wire, enabling further procedures within the vascularchannel in the second direction.
 14. The method according to claim 13further comprising the step of: confirming the placement of the initialwire into the lumen of the vascular channel through fluoroscopicimaging.
 15. A method for vascular access, the method comprising thesteps of: (a1) advancing a needle through a skin of a subject at anentry point and into a lumen of a vascular channel; (a2) placing a finewire through a lumen of the needle into the lumen of the vascularchannel in a first direction; (a3) removing the needle completely fromthe fine wire while leaving the fine wire in place; (a4) advancing overthe fine wire a dilator and a sheath into the lumen of the vascularchannel in the first direction; (a5) removing the dilator completelyfrom the fine wire while leaving the sheath in place; (a6) removing thefine wire completely from the sheath while leaving the sheath in place;(a7) advancing a first wire through the sheath into the vascular channelin the first direction; (a8) removing the sheath completely from thefirst wire while leaving the first wire in place; (b) advancing a curvedneedle over the first wire through the skin of the subject at the entrypoint and into the lumen of the vascular channel until the tip of thecurved needle is substantially horizontal or parallel to the vascularchannel; (c) removing the first wire completely from the curved needle;(d) advancing the curved needle until the tip of the curved needle exitsthe vascular channel and exits through the skin of the patient at anexit point proximal to the entry point; (e) advancing a second wire intoand out of a lumen of the curved needle; (f) removing the curved needlecompletely from the second wire while leaving the second wire in place;(g) from the exit point, advancing over the second wire a dual-lumenaccess director into the vascular channel in a second direction oppositethe first direction, wherein the dual-lumen access director receives thesecond wire in a first lumen that extends from the tip of the dual-lumenaccess director to the head of the dual-lumen access director; (h)advancing the dual-lumen access director until an oval orifice locatedproximal to the tip of the dual-lumen access director is just about toexit the vascular channel, wherein a second lumen extends from the headof the dual-lumen access director to the oval orifice of the dual-lumenaccess director; (i) advancing a third wire down the second lumen of thedual-lumen access director until the tip of the second wire exitsthrough the oval orifice and into the vascular channel; (j) removing thedual-lumen access director completely from the second and third wireswhile leaving the second and third wires in place; (k) removing thesecond wire completely from the vascular channel and out of the skin ofthe subject; and (l) advancing a sheath over the third wire, enablingfurther procedures within the vascular channel in the second direction.16. The method according to claim 15 further comprising the step of:confirming the placement of the initial wire into the lumen of thesuperficial femoral artery through fluoroscopic imaging.